from influential IGs, then unilateral actions by one country can change the ef-
fect of such messages. However, unilateral actions have not always been as
successful as expected. One explanation offered in this paper is that the initiator
of unilateral actions is the country with the highest expectation about its pros-
pects of influencing other countries’ decision processes. Since the country hold-
ing the highest expectation is likely to overestimate the true state, it is likely to
be disappointed. In conclusion, this paper both provides positive and negative
prospects for the initiator of unilateral actions as movements towards an effec-
tive control of the international environmental problem.
8. Conclusions
The analysis presented in this paper builds on the crucial assumption that uni-
lateral actions concern the revelation of information about the cost side. Is it
reasonable to expect that uncertainty relates to the cost side and not the damage
side? We believe that taking unilateral actions reveals the true costs. Once rele-
vant measures are implemented, information regarding their efficiency and their
costs are available. On the other hand, a unilateral action will not reveal the
damage costs (or equally, the benefits from reductions). In particular, if consid-
ering a global pollution problem, the effect of one country on the total stock of
pollution will probably be negligible, and no new information regarding the
damage cost functions is revealed. Moreover, compared to the model in section
5, taking into account the public choice model, unilateral actions as a cost re-
vealing mechanism becomes even more likely: If we look at the problems of
implementing the Kyoto-agreement, the US policymakers repeatedly claimed
that the costs of reductions were simply too high to justify the efforts can. Such
a statement can only be undermined if it is revealed that also for US costs of
reductions are low. We also believe that signalling as a mechanism of informa-
tion transmission in the way described in this paper is not unreasonable. The
reason is that countries are only convinced by hard facts (and not by a report
from a government hired consultancy agency), simply because incentives are
such that each country has an incentive to try to convince others that costs are
low. However, only when a country has verified that costs are low by imple-
36